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Reducing Bacteria Growth in Food

  1. Sep 10, 2010 #1
    Say we take a carrot... or steak (or whatever food you fancy) and put it in a sealed container along with a culture of 'normal' bacteria (I'm talking about the regular bacteria that would be present to decompose food).
    Now, here comes the question:
    What would be the most effective way to stop (or even sterilize) the bacteria culture in the container, without compromising the food product, so that no proteins (or any other healthy stuff like vitamins), or taste are lost from the food.

    I have thought about putting the food under pressure to kill the bacteria, or using CO2, but CO2 appears to lower the quality of the food.

    Other things I considered using:
    PEF
    Drying (compromises food)
    Antioxidants
    Ozone (apparently it breaks down the proteine in the food, and is a 'little' lethal ;P)

    Gimmi your best shot ^^
     
  2. jcsd
  3. Sep 10, 2010 #2

    Borek

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    Radiation.
     
  4. Sep 10, 2010 #3
    Wouldn't the radiation be accumulated in the food?

    And change the stucture of the food?
     
  5. Sep 10, 2010 #4

    D H

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    No, although that is one of the canards put out by the luddite anti-irradiation crowd. Irradiating food does not involve injecting radioactive substances into food. All that is done is to irradiate it with ionizing radiation. Low levels suffice to keep vegetables from sprouting. Higher levels are needed to kill the bacteria resident on/in the food. There is no change in the atomic makeup of the food.

    Yes, that's the point. However, this is also the point of any food preservation technology. The question is, how much does it change the structure of the food? Pasteurizing milk changes the structure of milk a whole lot more than does irradiating it.
     
  6. Sep 10, 2010 #5
    Hell yes, and it can't happen soon enough on a larger scale. I suspect irradiating chicken eggs would be more effective than selective pasteurization, and as D H has said of others situations, do less to change their structure.
     
  7. Sep 10, 2010 #6
    100% agreement, most forms of radation do no damage that your digestive system wasnt desgined to do in the first place. Radiation breaks chemical bonds, and so do the many of the enzymes of your digestive system. And no radation will not stick around unless it is contaminated with a radioactive element. No one who supports irradiateing food has ever sudgested doing such. Usually it involves exposeing the food to gamma rays whitch are "extreemly high energy" light waves. They are very good at killing all forms of life. Opening a package of carrots and knowing that there are only a handfull of living cells inside should make you feel very very happy about living in a first world country, not as the luddites say that youll become a radation zombie.
     
  8. Sep 10, 2010 #7
    ...and some of us think that becoming a nation of radioactive zombies would be a bit... cool? :wink:

    The way some people talk about radiation re: food, you'd think people were talking about spraying radioactive cobalt, bismuth, with a tritium chaser on everything!
     
  9. Sep 10, 2010 #8
    Been playing a bit too much Fallout I see!

    It dose sadden me that enviromentalist have formed a religion that hates appropriate progress and wishes the entire world to revert to the stoneage.
     
  10. Sep 10, 2010 #9
    Not all of them, for instance I love nature and animals, but I'm not against human progress. Extremists of any stripe seem to want us in the stone-age... it's a weird trend. Amish, Taliban, Environmental Extremists... common theme.

    The only way to get through this period in our unfortunate impact on the world is progress... no guarantees that will work, but barring a mass-extinction event the stone-age has passed. It's a pity that "environmentalist" is conflated with an extremist, in much the way that Muslim and terrorist have been. Yeah, both groups have their psychotic Luddites... and as always they seem to have the loudest voices and the most obvious impact. Then, for political reasons it becomes convenient to call anyone with aspirations to be responsible regarding the environment a tree-hugger.

    Back to the OP, I don't even see how irradiating food for safety is an environmental issue to begin with! It's just scared people who don't understand the effects of radiation, which is really a failure of education.
     
  11. Sep 10, 2010 #10
    Forgive me for speaking so broadly, extreemist is what i ment by religion. I support everything that can be done to limit mans impact on the planet, however by opposeing so many different ways forward the give a default victory to those who dont care. But this is getting off topic.
     
  12. Sep 10, 2010 #11
    Gotcha, but it was interesting, and I agree with you.
     
  13. Sep 10, 2010 #12

    Borek

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  14. Sep 13, 2010 #13
    Thanks for the link and all the good replies :-)
     
  15. Sep 13, 2010 #14
    On a different tack than most of the contributions to this thread, and not sure if this is really what you are looking for, Physics<3<3<3, but this is pretty much what some of the equipment made by the company I work for does. Understand, we are not in food manufacture ourselves, we are engineers, but some of our customers make these cook-chilled (as opposed to frozen) convenience meals. The basic idea is that once the product is cooked, it is chilled very rapidly under vacuum. It is actually more technical than that. The problem is that excessive use of vacuum would destroy flavour, so the vacuum is applied to a very closely controlled curve. The key idea is that the product has a significantly increased shelf life, due to reduced bacterial growth exactly as you suggest, but flavour is not impaired. How irradiation affects flavour, I’m not sure.
     
  16. Sep 20, 2010 #15
    Cool thanks for the reply Ken Natton, I didn't think abot that before you posted.

    So I decided to use UV lighting instead of radiation (since its illegal to use on my product). As I understand, UV light should release ionised radiation in potent doses, able enough to kill off any bacteria.
     
  17. Sep 20, 2010 #16

    Borek

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    Yes and no. UV kills bacteria, but it doesn't penetrate deep - so whatever is 'inside' may easily survive.
     
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